Hydrangea plant named ‘SMNHMSIGMA’

ABSTRACT

A new and distinct cultivar of  Hydrangea  plant named ‘SMNHMSIGMA’, characterized by its compact, upright, outwardly spreading and mounding plant habit; strong and sturdy stems; remontant flowering habit; dark green-colored leaves; mophead-type inflorescences with intense deep pink-colored sterile flowers that can easily be “blued” with aluminum sulfate treatments; and good garden performance.

Botanical designation: Hydrangea macrophylla.

Cultivar denomination: ‘SMNHMSIGMA’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct Hydrangea plant, botanically known as Hydrangea macrophylla and hereinafter referred to by the name ‘SMNHMSIGMA’.

The new Hydrangea plant is a product of a planned breeding program conducted by the Inventor in Grand Haven, Mich. The objective of the breeding program was to develop new compact and reblooming Hydrangea plants with strong stems and attractive inflorescences.

The new Hydrangea plant originated from an open-pollination in July, 2008 of Hydrangea macrophylla ‘Robert’, disclosed in U.S. Plant Pat. No. 20,020, as the female, or seed parent and an unknown selection of Hydrangea macrophylla, as the male, or pollen, parent. The new Hydrangea plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated open-pollination in a controlled environment in Grand Haven, Mich. in June, 2011.

Asexual reproduction of the new Hydrangea plant by softwood cuttings in a controlled environment in Grand Haven, Mich. since June, 2011 has shown that the unique features of this new Hydrangea plant are stable and reproduced true to type in successive generations of asexual reproduction.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘SMNHMSIGMA’. These characteristics in combination distinguish ‘SMNHMSIGMA’ as a new and distinct Hydrangea plant:

-   -   1. Compact, upright, outwardly spreading and mounding plant         habit.     -   2. Strong and sturdy stems.     -   3. Remontant flowering habit.     -   4. Dark green-colored leaves.     -   5. Mophead-type inflorescences with intense dark pink-colored         sterile flowers that can easily be “blued” with aluminum sulfate         treatments.     -   6. Good garden performance.

Plants of the new Hydrangea differ from plants of the female parent, ‘Robert’, in the following characteristics:

-   -   1. Plants of the new Hydrangea have stronger stems than plants         of ‘Robert’.     -   2. Sterile flower sepals of plants of the new Hydrangea are         richer and more intense in color than sterile flower sepals of         plants of ‘Robert’.     -   3. Plants of the new Hydrangea are more easily “blued” with         aluminum sulfate than plants of ‘Robert’.     -   4. Plants of the new Hydrangea have a stronger reblooming habit         than plants of ‘Robert’.

Plants of the new Hydrangea can be compared to plants of Hydrangea macrophylla ‘Nikko Blue’, not patented. In side-by-side comparisons, plants of the new Hydrangea differed primarily from plants of ‘Nikko Blue’ in the following characteristics:

-   -   1. Sterile flower sepals of plants of the new Hydrangea were         darker and more intense in color than sterile flower sepals of         plants of ‘Nikko Blue’.     -   2. Plants of the new Hydrangea had a stronger reblooming habit         than plants of ‘Nikko Blue’.

Plants of the new Hydrangea can also be compared to plants of Hydrangea macrophylla ‘Berner’, disclosed in U.S. Plant Pat. No. 22,329. In side-by-side comparisons, plants of the new Hydrangea differed primarily from plants of ‘Berner’ in the following characteristics:

-   -   1. Sterile flower sepals of plants of the new Hydrangea were         smaller and richer and more intense in color than sterile flower         sepals of plants of ‘Berner’.     -   2. Plants of the new Hydrangea had a stronger reblooming habit         than plants of ‘Berner’.     -   3. Plants of the new Hydrangea were more easily “blued” with         aluminum sulfate than plants of ‘Berner’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the unique appearance of the new Hydrangea plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Hydrangea plant.

The photograph on the first sheet comprises a side perspective view of a typical flowering plant of ‘SMNHMSIGMA’ grown in an outdoor nursery.

The photograph on the second sheet is a close-up view of typical inflorescences of ‘SMNHMSIGMA’; the inflorescence on the left is from a plant that was not treated with aluminum sulfate and the inflorescence on the right is from a plant that was treated with aluminum sulfate.

DETAILED BOTANICAL DESCRIPTION

Plants used for the aforementioned photographs and the following description were grown during the summer in three-gallon containers in a polypropylene-covered shadehouse in Grand Haven, Mich. and under cultural practices typical of commercial Hydrangea production. During the production of the plants, day temperatures ranged from 18° C. to 27° C. and night temperatures ranged from 5° C. to 10° C. Plants of the new Hydrangea were two years old when the photographs and description were taken. Plants were overwintered in a polyethylene-covered greenhouse. Some plants were treated with aluminum sulfate to “blue” the flowers. During the production of the plants, the soil pH ranged from 5.0 to 6.0. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 1995 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical description: Hydrangea macrophylla ‘SMNHMSIGMA’. -   Parentage:     -   -   Female, or seed, parent.—Hydrangea macrophylla ‘Robert’,             disclosed in U.S. Plant Pat. No. 20,020.         -   Male, or pollen, parent.—Unknown selection of Hydrangea             macrophylla, not patented. -   Propagation:     -   -   Type cutting.—By softwood cuttings.         -   Time to initiate roots, summer.—About 18 days at             temperatures about 27° C.         -   Time to produce a rooted young plant, summer.—About 60 days             at temperatures about 27° C.         -   Root description.—Fine to thick; fibrous; white and brown in             color.         -   Rooting habit.—Freely branching; dense. -   Plant description:     -   -   Plant form and growth habit.—Perennial deciduous shrub;             compact, upright, outwardly spreading and mounding plant             habit; strong and sturdy lateral branches; freely branching             habit with about 36 lateral branches developing per plant;             vigorous growth habit.         -   Plant height.—About 66 cm.         -   Plant diameter or area of spread.—About 82 cm.         -   Lateral branches.—Length: About 34 cm. Diameter: About 7 mm.             Internode length: About 6 cm. Texture: Smooth, glabrous.             Strength: Strong, sturdy. Aspect: Erect to about 45° from             vertical. Color: Close to 145B. -   Leaf description:     -   -   Arrangement.—Opposite, simple.         -   Length.—About 16.5 cm.         -   Width.—About 8 cm to 11 cm.         -   Shape.—Ovate.         -   Apex.—Acute to acuminate.         -   Base.—Cuneate.         -   Margin.—Serrate.         -   Texture, upper and lower surfaces.—Smooth, glabrous;             leathery.         -   Venation pattern.—Pinnate.         -   Color.—Developing leaves, upper surface: Close to 137A.             Developing leaves, lower surface: Close to 137C. Fully             expanded leaves, upper surface: Close to 139A; venation,             close to 138A. Fully expanded leaves, lower surface: Close             to 137C; venation, close to 137C and 59A.         -   Petioles.—Length: About 3.5 cm. Diameter: About 4 mm.             Texture, upper and lower surfaces: Smooth, glabrous. Color,             upper surface: Close to 137C. Color, lower surface: Close to             137C and 59A. -   Flower description:     -   -   Flower type and habit.—Single sterile and fertile flowers             arranged on terminal mophead cymes that are roughly             hemispherical in shape; flowers face upright to outwardly.         -   Fragrance.—None detected.         -   Natural flowering season.—Plants flower throughout the             summer in Grand Haven, Mich.; flowering remontant; flowers             not persistent.         -   Quantity of flowers.—Freely flowering habit; about 91             fertile flowers and about 306 sterile flowers developing per             inflorescence.         -   Inflorescence height.—About 13 cm.         -   Inflorescence diameter.—About 19 cm.         -   Flower diameter, fertile flowers.—About 2.6 mm.         -   Flower depth (height), fertile flowers.—About 2.2 mm.         -   Flower diameter, sterile flowers.—About 3 cm to 4 cm.         -   Flower depth (height), sterile flowers.—About 2.5 cm.         -   Flower buds, fertile and sterile flowers.—Length: About             3 mm. Diameter: About 3 mm. Shape: Obovate. Color, not             treated with aluminum sulfate: Close to 145B and 73C. Color,             treated with aluminum sulfate: Close to 145B and 104D.         -   Petals, fertile flowers.—Quantity and arrangement: About             five in a single whorl. Length: About 2 mm. Width: About             1.2 mm. Shape: Ovate. Apex: Acute. Base: Cuneate. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color: When opening, upper surface: Close to 145D; towards             the margins, close to 145B; towards the apex, close to 63A.             When opening, lower surface: Blending from base towards the             apex and margins, close to 145D, 145C, 145B and 145A. Fully             opened, upper surface: Close to 145D; towards the margins,             close to 145B; towards the apex, close to 63A; color does             not change with development. Fully opened, lower surface:             Blending from base towards the center, close to 145D and             145C; towards the apex, close to 63D; occasional spot, close             to 145A; color does not change with development.         -   Petals, sterile flowers.—Quantity and arrangement: About             four in a single whorl. Length: About 2 mm. Width: About             1 mm. Shape: Ovate. Apex: Acute. Base: Cuneate. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color, plants not treated with aluminum sulfate: When             opening, upper and lower surfaces: Close to 73C. Fully             opened, upper surface: Close to 73C; with development, inner             stripes (venation) becoming closer to 64D and 63D. Fully             opened, lower surface: Close to 73C; with development, inner             stripes (venation) becoming closer to 62D and 73B. Color,             plants treated with aluminum sulfate: When opening, upper             and lower surfaces: Close to 104D. Fully opened, upper and             lower surfaces: Close to 104D; color does not change with             development.         -   Sepals, sterile flowers only.—Quantity and arrangement:             About four in a single whorl. Length: About 2 cm. Width:             About 2.2 cm. Shape: Ovate. Apex: Acute. Base: Obtuse.             Margin: Entire. Texture, upper and lower surfaces: Smooth,             glabrous. Color, plants not treated with aluminum sulfate:             When opening, upper surface: Close to 68A; towards the base,             close to 145B. When opening, lower surface: Close to 68C.             Fully opened, upper surface: Close to 68A; with development,             inner stripes (venation) becoming closer to 64D and 63D.             Fully opened, lower surface: Close to 68C; with development,             inner stripes (venation) becoming closer to 62D and 73B.             Color, plants treated with aluminum sulfate: When opening,             upper surface: Close to 93B. When opening, lower surface:             Close to 93D. Fully opened, upper surface: Close to 93B;             color does not change with development. Fully opened, lower             surface: Close to 93C; color does not change with             development.         -   Pedicels, fertile flowers.—Length: About 3 mm. Diameter:             About 1 mm. Angle: About 15° to 35° from inflorescence axis.             Strength: Strong, sturdy. Texture: Smooth, glabrous. Color:             Close to 145B.         -   Pedicels, sterile flowers.—Length: About 1.5 cm. Diameter:             About 1 mm. Angle: About 45° from inflorescence axis.             Strength: Strong, sturdy. Texture: Smooth, glabrous. Color,             plants not treated with aluminum sulfate: Close to 145B and             68A. Color, plants treated with aluminum sulfate: Close to             145B and 93C.         -   Reproductive organs, fertile flowers.—Stamens: Quantity per             flower: About eight to ten. Filament length: About 1.2 mm.             Filament color: Close to 145D. Anther shape: Round. Anther             length: About 0.25 mm. Anther color: Close to 145D. Pollen             amount: Scarce. Pollen color: Close to 155B. Pistils: Pistil             quantity per flower: One, two to three-lobed. Pistil length:             About 0.7 mm. Stigma shape: Oblong. Stigma color: Close to             155B and 145D. Style length: About 0.5 mm. Style color:             Close to 155B and 145D. Ovary color: Close to 155B and 145B.         -   Reproductive organs, sterile flowers.—Stamens: Quantity per             flower: If present, about six to eight. Filament length:             About 1.2 mm. Filament color: Close to 145D. Anther shape:             Round. Anther length: About 0.25 mm. Anther color: Close to             145D. Pollen amount: Scarce. Pollen color: Close to 155B.             Pistils: Pistil quantity per flower: One, two to             three-lobed. Pistil length: About 0.7 mm. Stigma shape:             Oblong. Stigma color: Close to 155B and 145D. Style length:             About 0.5 mm. Style color: Close to 155B and 145D. Ovary             color: Close to 155B and 145B.         -   Seeds, observed on fertile flowers only.—Quantity per             inflorescence: Numerous. Size: Less than 0.1 mm by less than             0.1 mm; dust-like. Color: Brown. -   Disease & pest resistance: Plants of the new Hydrangea have been     observed to be resistant to Mildew. Plants of the new Hydrangea have     not been observed to be resistant to pests and other pathogens     common to Hydrangea plants. -   Garden performance: Plants of the new Hydrangea have been shown to     exhibit good garden performance. Plants of the new Hydrangea have     been observed to tolerate temperatures ranging from −30° C. to 36°     C. 

It is claimed:
 1. A new and distinct Hydrangea plant named ‘SMNHMSIGMA’ as illustrated and described. 